2021-09-21 02:43:12

by Colin King

Subject: [PATCH][next] hwmon: (mlxreg-fan): Fix out of bounds read on array fan->pwm

From: Colin Ian King <[email protected]>

Array fan->pwm[] is MLXREG_FAN_MAX_PWM elements in size, however the
for-loop has a off-by-one error causing index i to be out of range
causing an out of bounds read on the array. Fix this by replacing
the <= operator with < in the for-loop.

Addresses-Coverity: ("Out-of-bounds read")
Fixes: 35edbaab3bbf ("hwmon: (mlxreg-fan) Extend driver to support multiply cooling devices")
Signed-off-by: Colin Ian King <[email protected]>
---
drivers/hwmon/mlxreg-fan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c
index 35228ed112d7..feab9ec6a6ca 100644
--- a/drivers/hwmon/mlxreg-fan.c
+++ b/drivers/hwmon/mlxreg-fan.c
@@ -554,7 +554,7 @@ static int mlxreg_fan_cooling_config(struct device *dev, struct mlxreg_fan *fan)
{
int i, j;

- for (i = 0; i <= MLXREG_FAN_MAX_PWM; i++) {
+ for (i = 0; i < MLXREG_FAN_MAX_PWM; i++) {
struct mlxreg_fan_pwm *pwm = &fan->pwm[i];

if (!pwm->connected)
--
2.32.0

2021-09-24 01:07:53

by Guenter Roeck

Subject: Re: [PATCH][next] hwmon: (mlxreg-fan): Fix out of bounds read on array fan->pwm

On Mon, Sep 20, 2021 at 07:09:21PM +0100, Colin King wrote:
> From: Colin Ian King <[email protected]>
>
> Array fan->pwm[] is MLXREG_FAN_MAX_PWM elements in size, however the
> for-loop has a off-by-one error causing index i to be out of range
> causing an out of bounds read on the array. Fix this by replacing
> the <= operator with < in the for-loop.
>
> Addresses-Coverity: ("Out-of-bounds read")
> Fixes: 35edbaab3bbf ("hwmon: (mlxreg-fan) Extend driver to support multiply cooling devices")
> Signed-off-by: Colin Ian King <[email protected]>

Applied.

Thanks,
Guenter

> ---
> drivers/hwmon/mlxreg-fan.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c
> index 35228ed112d7..feab9ec6a6ca 100644
> --- a/drivers/hwmon/mlxreg-fan.c
> +++ b/drivers/hwmon/mlxreg-fan.c
> @@ -554,7 +554,7 @@ static int mlxreg_fan_cooling_config(struct device *dev, struct mlxreg_fan *fan)
> {
> int i, j;
>
> - for (i = 0; i <= MLXREG_FAN_MAX_PWM; i++) {
> + for (i = 0; i < MLXREG_FAN_MAX_PWM; i++) {
> struct mlxreg_fan_pwm *pwm = &fan->pwm[i];
>
> if (!pwm->connected)